Frictional resistance is an important part of the total resistance of a ship, especially when the Froude number is small. There exists different ways to reduce it, like riblets, polymer injection, air ... [more ▼]

Frictional resistance is an important part of the total resistance of a ship, especially when the Froude number is small. There exists different ways to reduce it, like riblets, polymer injection, air lubrication and air cavity. The first two techniques are hard to implement for full-scale ships. The air lubrication is subjected to plenty of research for around twenty years and could lead to resistance reduction up to 80%. Unfortunately, full-scale tests do not present the same results. The principle of air cavity ships is quite different, in the sense that air is blocked under the hull. The system exists for more than 100 years, but does not seem to convince the naval architects, although it can reduce the resistance up to 20%. The problem is that it can increase the resistance. Better knowledge of the phenomena is then necessary. [less ▲]

Nowadays productibility has become a major design attribute for shipbuilding industry. If a ship cannot be manufactured or assembled efficiently, it is not properly designed. To increase the ... [more ▼]

Nowadays productibility has become a major design attribute for shipbuilding industry. If a ship cannot be manufactured or assembled efficiently, it is not properly designed. To increase the productibility of ships, the scientific community and shipyards has developed the concept of Design For Production (DFP) which can be defined as "Design to reduce production costs to a minimum, compatible with the requirements of the vessel to fulfil its operational functions with acceptable safety, reliability and efficiency". DFP optimises all the manufacturing functions (fabrication, assembly, test, procurement, delivery, service, repair, etc.) that reduce the production work content while still meeting the specified design requirements and quality. The goal is to include the impact of design decisions on the production process. Time pressures on commercial ship contracts result in the overlapping of phases of design development, procurement and production. This makes the impact of engineering changes more difficult to manage. There is a need to systematically study the detail design process and its impact on construction with the objective to improve the process and its integration with construction. DFP can significantly reduce the costs, since ships can be quickly assembled from fewer parts. Thus, ships are easier to build and assemble, in less time, with better quality. Designers will save time and money by the reduction of the production complexity. [less ▲]

The recent development of medium-speed monohull passenger ferries has shown their importance for certain routes. The aim of the intensive studies performed in the recent years is to fulfil the pending ... [more ▼]

The recent development of medium-speed monohull passenger ferries has shown their importance for certain routes. The aim of the intensive studies performed in the recent years is to fulfil the pending technical and environmental issues concerning the HSC crafts. They operate at the Froude number range of 0.55 to 0.80 which is beyond the last hump of the wave resistance curve. In fact, they need a high power to maintain their operation speeds. The present project is to find the best design based on the layout of the passenger arrangement and the hull form configurations. The layout includes the seat arrangement and the distribution of passengers at the main and upper decks. Due to the lack of design data base of those kinds of semi-planning ships, a parent ship of 250 passengers is considered in this study. During the design process, the rules and mandatory issues are taken into account. The results of the design parameters and general layout of a series of parent ships are presented in this paper. The results will be applied in a future parametric study, particularly to find the best layout and hull form with the minimum engine power. Keywords: Ship design, general arrangement, engine power, passenger vessel [less ▲]

LBR-5 is a tool for early design stage. Taking into account numerous kinds of constraints – structural, geometrical, etc. – an optimum scantling can quickly been found. In the framework of IMPROVE ... [more ▼]

LBR-5 is a tool for early design stage. Taking into account numerous kinds of constraints – structural, geometrical, etc. – an optimum scantling can quickly been found. In the framework of IMPROVE European project many new modules have been implemented to increase the quality of the optimised scantling. Mainly 6 major changes have been brought: implementation of a sloshing module, a fatigue module, a multi-structure module, a multi-materials module, a life cycle cost module and finally a vibration module. Tests to validate these modules have been carried out on the three ships studied in the IMPROVE project: a LNG, a Chemical Tanker and a ROPAX. [less ▲]

in Conference on Computer Applications and Information Technology in the Maritime Industries (COMPIT) (2008, April)

This paper relates to the development of a new concept of 220.000 m³ LNG designed by AKERYARDS France. This work is performed in the framework of FP6 IMPROVE project. The first phase of the activity ... [more ▼]

This paper relates to the development of a new concept of 220.000 m³ LNG designed by AKERYARDS France. This work is performed in the framework of FP6 IMPROVE project. The first phase of the activity related to the identification of stakeholder’s requirements and the definition of key performance indicators. In parallel, several calculations have been performed to test the existing tools and to evaluate the potential gain at the concept design. These activities, associated with the definition of a 220000 m³ QuatarFlex prototype, including the aspects related to the naval architecture and general arrangement, have been re-grouped in the so-called “first design loop”. The second phase concerns the development of new modules to be integrated in the optimization tools in order to satisfy the requirements defined in the first phase. The final phase will be the application of the new (improved) optimization tools for the final LNG product. We highlight that the main target will be the multi-objective structural optimization of the prototype defined by “the first design loop”. However, some feed-back concerning the naval architecture point of view could be expected in this phase. The aim of the paper is to present the results of the first phase, as well as an overview of the analyses carried out during the “first design loop”. Details about the different methodologies proposed for the second phase of the development are given. [less ▲]

The research group MRN04 has made a study of modernization of frigates of the Belgian Navy. The modernization includes fitting out of a landing area for an 11 tonnes helicopter, modifying the ... [more ▼]

The research group MRN04 has made a study of modernization of frigates of the Belgian Navy. The modernization includes fitting out of a landing area for an 11 tonnes helicopter, modifying the superstructure to solve the problems of cracks and reducing the radar cross section. The proposal of the group MRN04 consists of widening and stiffness the stern deck in order to permit landing of a helicopter, surrounding the existing superstructure by a new envelop having a better furtivity. The resistance of the helicopter landing area and the rigidity of the superstructure has been estimated by structural computations by finite elements method, which permits to choose the most adequate structure. Once the weight of the new elements is known, a new estimation of the weight is established. It permits to calculate the draft and the trim, and serves as the data to calculate the ship resistance. In fact, the speed of the frigate, as a crucial point, should not decrease too much. The ship resistance will be obtained by means of model tests in the towing tank in the University of Liège. The study shows the possibility to lay out a landing area for a helicopter of 11 tonnes as well as to decrease significantly the radar cross section, without severe reduction of the frigate speed. [less ▲]